A Polytech High School employee was taken into police custody at the school this morning after staff there called police to say he was acting suspiciously.

According to Delaware Department of Education Public Information Office Alison Kepner, an employee who had been out on medical leave, entered the school’s campus through an outbuilding, where he was met by other school employees.

Polytech Principal Jason Peel, in a message posted on the school’s homepage, described the employee as acting “suspicious” and said it prompted other staff members to call 9-1-1 an institute a lockdown at the school.

The incident happened around 11 a.m., Peel wrote.

Parents received an “Alert Now” message – a service used to deliver emergency communications – from the district to apprise them of the situation.

Kepner said students and staff within the school were never in danger. The school was on lockdown for 30 minutes before classes resumed at their normal schedule.

Police remained on the scene to provide extra security and peace of mind for the students, Peel wrote.

Delaware State Police Cpl. Gary Fournier said the suspect was in police custody.

“We are still investigating the situation, there are currently no charges, we are conducting interviews,” Fournier said.